Introduction: Analgesia from controlled injections of local anaesthetic into the lumbar zygapohysial joint (z-joint) has been accepted as the standard for diagnosis of z-joint pain. Little is known about the placebo-response rate. Aim of this pilot study is to validate the fluoroscopically controlled z-joint-injection (ZJI) as an instrument for diagnosis of degenerative symptomatic z-joint disease.

Material and Methods: Due to degenerative lumbar spine syndrome 50 z-joints (L5/5: 27; L5/S1 23) were injected three times in a single blinded trial bilaterally. According to a randomisation protocol, using the oblique needle technique the ZJI were done with an local anaesthetic (LA: 1.5 ml 0.5% Scandicain), a saline placebo (sodium: 1.5ml 0.9% NaCl) and with no agent (sicca punction). The pain level before and after the injections (30 min, 1 and 2–3 hours) was documented by the patient on a 10pts.-VAS. Improvement in the pain level after an FJI is defined as responder. A responder reacts false positive if the degree of effectiveness of the placebo-FJI is the same or better than the response to LA. A patient reacts false negative if the pain diminution after LA application is lower than after placebo.

Results: Preliminary results regarding the reactions 30 min after injection are presented. 26% were non-responder and 52.9% LA-responder. The sicca response rate was 38%, for sodium it was 46%. Reaction after sicca-FJI was false positive in 24%, after sodium-FJI in 32% of cases. 38% reacted false negative to LA-injection. The order of the agent application didn’t have significant influence on the responder rates and also not on the extent of contradictory effects.

Conclusions: Despite numerous examinations none could sufficiently evaluate accurate reliable predictors for positive ZJI-responders till now. This is confirmed by our high LA-non-responder-rate of 48.1%. However, only a placebo injection can absolutely exclude a true placebo response. Placebo responses seem to be common. High specificity (minimization of the false positive results) and sensitivity (minimization of the false negative results) are characters for a good diagnostic test. In literature, the specificity of the intraarticular facet block as a diagnostic test for facet joint disease is currently unknown. Capsular rupture with epidural and periarticular diffusion is probably responsible for many false positive findings. Regarding our results, the validity of only one ZJI is not acceptable and shouldn’t be consulted as a diagnostic method for the identification of a facet joint syndrome, therefore. Pain relief after ZJI is a poor predictor of clinical outcome of posterolateral lumbosacral fusions when based on single blocks. Corresponding further examinations are necessary also regarding the ZJI-reliability.

Introduction: Filling of bone defects is a significant challenge in Orthopaedic Surgery. Human fresh-frozen allograft is still the most effective bone graft substitution material («gold standard»), guaranteeing all essential biological and physiochemical demands (osteogenic, osteoinductive, and osteoconductive) when the necessary amount of autologous bone is not available. Using donor screening recommendations, more than 50 % of potential donors have to be excluded. With increasing incidence for revision hip surgery and especially acetabular reconstructions, a hospital associated bone bank has difficulties meeting demand. The aim of this study is to evaluate the balance and resource utilisation of a hospital associated bone bank for fresh-frozen allografts and the correlation to commercial alternatives regarding cost effectiveness.

Method: For evaluation of resource utilisation and cost effectiveness of a hospital associated bone bank, all donation processes and the details of allograft use were analysed and summarized within a period of 30 months. Given the increasing disproportion of demand and availability, the reasons for exclusion, especially for exclusion during the preservation period, were carefully scrutinized. The costs of installation and maintenance of the bone bank, as well as all costs in the screening process were balanced to calculate the «per head»-price. The results were compared to commercial alternatives.

Results: Within the period of evaluation 632 femoral heads were available for donation. Through the screening process 359 femoral heads (56.8%) met at least one criterion for exclusion. At the end of the observation period of six months and after HIV retesting, 246 allografts met all criteria for use. The mean period between inclusion in the bone bank and release was 10.9 5.0 months (range 6.0–30.8).

50.8% of released allografts (125 heads) were used in revision arthroplasty. In spine surgery 83 allografts (33.7%) were implanted in spinal fusions and for cage filling during vertebral body replacement. Thirty-two grafts (13.0%) were used in miscellaneous surgeries with minor bone demand.

The costs per donation were 92, with personnel costs the price per head was 140. The price range for commercial alternatives starts at 100 for 1 cm.

Conclusion: A hospital associated bone bank for fresh-frozen allografts is still an effective and cost effective method to maintain material for bone defect filling. To meet demand, information and communication to donors has to be increased to get the HIV-retests. Additionally, division of donations into smaller portions helps to decrease waste in surgeries where less bone is required.